The Impact of Different Regions of Interest on Shear Wave Elastography Assessment of the Meniscus in the Knee Joint.

RATIONALE AND OBJECTIVES: To investigate the impact of different regions of interest (ROI) on the assessment of shear wave elastography (SWE) in evaluating the meniscus of the knee joint. MATERIALS AND METHODS: After ethical approval, a total of 141 participants were enrolled in this prospective study from February to October 2023. SWE was utilized to evaluate the anterior horn of the lateral meniscus (LM) and medial meniscus (MM), using two different ROIs (ROI-Small and ROI-Trace) to measure the elastic mean value (Emean) and elastic maximum value (Emax). The differences in elasticity values between the normal menisci and torn menisci were compared, and the impact of different ROI selection methods on the diagnostic performance of elastic parameters in the torn menisci was assessed using receiver operating characteristic (ROC) curves. RESULTS: In Emean comparison, only MM in the tear group showed higher ROI-S than ROI-T. When comparing Emax, all ROI-T values were higher than the ROI-S values, and this difference was statistically significant. Different sizes of ROI did not significantly impact the diagnostic performance of Emean in LM and MM, nor the diagnostic effectiveness of Emax in LM. However, only the area under the curve (AUC) of MM for Emax in both ROI-S and ROI-T showed a statistically significant difference. CONCLUSION: The shear wave elasticity values and diagnostic performance may vary depending on the ROI settings. Therefore, it is recommended to use a 2 mm diameter ROI placed at the central position of the meniscus, with Emean as the elasticity index.

Expansion and contraction of lake basin shape the genetic structure of Sinocyclocheilus (Osteichthyes: Cypriniformes: Cyprinidae) populations in Central Yunnan, China.

Geological events can strongly affect the genetic structures and differentiation of fish populations. Especially, as an endemic fish of the genus Sinocyclocheilus in the Yunnan-Guizhou Plateau, the effects of key geological events on the distributions and genetic structures remain poorly understood. Examining the phylogeographic patterns of Sinocyclocheilus fishes can be useful for elucidating the spatio-temporal dynamics of their population size, dispersal history and extent of geographical isolation, thereby providing a theoretical basis for their protection. Here, we used single nucleotide polymorphisms (SNP) method to investigate the phylogeographic patterns of Sinocyclocheilus fishes. Our analysis supports the endemicity of Sinocyclocheilus, but the samples of different regions of Sinocyclocheilus contain multiple ancestral components, which displayed more admixed and diversified genetic components, this may be due to the polymorphism of the ancestors themselves, or gene infiltration caused by hybridization between adjacent species of Sinocyclocheilus. We estimate that the most recent common ancestor (MRCA) of Sinocyclocheilus fish in the Central Yunnan Basin at approximately 3.75~3.11 Ma, and infer that the evolution of Sinocyclocheilus in the central Yunnan Basin is closely related to the formation of plateau lakes (around 4.0~0.02 Ma), and identifies the formation of Dianchi Lake and Fuxian Lake as key geological events shaping Sinocyclocheilus population structure. It is also the first time to prove that the altitude change has a great influence on the genetic variation among the populations of Sinocyclocheilus.

Effects of water-soluble chitosan on Hylotelephium spectabile and soybean growth, as well as Cd uptake and phytoextraction efficiency in a co-planting cultivation system.

Intercropping a Cd-accumulator with economically valuable crops is common in slightly or moderately Cd-polluted farmland soils. A field experiment was conducted to evaluate the effects of water-soluble chitosan (WSC) on the growth and Cd uptake of the Cd-accumulator Hylotelephium spectabile and soybean (Glycine max) during a co-cultivation in Cd-contaminated agricultural soil (WSC, 0 and 10 g·m-2). The results indicated that soybean yields were highest in response to the intercropping and WSC treatment. The results from the field trials generally showed that intercropping and WSC treatments significantly decreased Cd concentrations in inedible parts of soybean by 42.9-72.1% (except for stems), in the meantime, increased 95.8%-334.6% in shoot and root tissues of H. spectabile compared with the control (p < 0.05). The data revealed that Cd uptake was highest for H. spectabile during the intercropping and WSC treatment. The application of WSC in the intercropping system significantly increased the uptake of Cd by H. spectabile, but not by soybean. The findings of this study suggest that combining an intercropping system with a WSC treatment may be better for remediating Cd-contaminated soils than other methods involving the growth of a single hyperaccumulator.

This paper clearly focused on the accumulation and uptake of Cd in the system of intercropping of Cd-accumulator (Hylotelephium spectable) and soybean (Glycine max) grown in Cd-polluted farmland soils supplied with water-soluble chitosan (WSC) under field conditions. Some studies mainly focused on active agent to promote remediation efficiency of (hyper) accumulators. This study indicated that combining the intercropping system with WSC may be better for remediating Cd-contaminated soils than the methods involving a single hyperaccumulator.

[Distribution Characteristics and Risk Assessment of Heavy Metal Pollution in Farmland Soils and Crops in Luancheng, Shijiazhuang City].

In order to explore the distribution characteristics of heavy metal contamination of farmland soil surrounding Luancheng town, Shijiazhuang City, Henan province, the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the surface soil and crops were determined and assessed. The principal components were also analyzed for source apportionment. The heavy metal concentrations in crops were further detected, and the non-carcinogenic health risks in the study area were evaluated using the probabilistic risk assessment method, as to provide a theoretical basis for the treatment, prevention, and control of heavy metal pollution in farmland soil in Luancheng. According to the results, ω(Cd), ω(Cr), ω(Cu), ω(Pb), and ω(Zn) in the soils were 0.06-1.08, 22.14-473.47, 12.83-150.74, 10.75-577.72, and 62.23-652.78 mg·kg-1, which exceeded the standard with over-standard rates reaching 1.83%, 1.22%, 0.61%, 0.61%, and 1.22%, respectively. Further, Cd and Pb were transported into crops, in which Cd concentrations exceeded the standard in some corn samples, and Cd and Pb concentrations exceeded the standard in some wheat samples. The total non-carcinogenic health risks (TTHQ) to the human body caused by the consumption of heavy metals in corn grown in the study area were all less than 1, with no obvious negative effects, and TTHQ was higher than 1 in wheat, increasing the likelihood of negative impacts on the human body. With the influence of the distribution of pollution-related enterprises in the industrial zone, heavy metal concentrations were higher in the south, west, and middle directions of the study area. Among them, the study area soil was slightly contaminated by Cd (Level 1). Cd and Hg had a slight potential ecological risk (Level 2), whereas other heavy metals had low potential ecological risk (Level 1). In general, most of the surface cultivated soil was not obviously polluted by heavy metals in the study area. According to the PMF results and survey, we speculated that soil heavy metals mainly came from soil parent material (52.05%), artificial pollution sources (historical sewage irrigation and industrial manufacture) (32.98%), and atmospheric deposition (14.97%). To summarize, the study area should be divided into a priority protection category and safe utilization category. The input of pollution sources should be strictly controlled for the priority protection category, and alternative planting, rotating, and fallow should be implemented for the safe utilization category to reduce the risk of standard-exceeding agricultural products.

Water-soluble chitosan and phytoremediation efficiency of two Brassica napus L. cultivars in cadmium-contaminated farmland soils.

Pot and field trials were conducted to investigate Cd uptake and phytoremediation efficiency of two Brassica napus cultivars (QY-1 and SYH) with applied water-soluble chitosan (WSC, Pot: 0, 2% and 4%; Field: 0 and 10 g·m-2) grown in Cd-contaminated soils. The results from the pot and field trials generally showed that WSC treatments significantly increased Cd concentrations in shoot and root tissues by 33.77-159.71% (except for SYH/JY) and 7.42-168.71% of two B. napus cultivars compared with the control (p < 0.05). The uptake of Cd by shoots of SYH was obviously higher than by shoots of QY-1 treated with WSC under pot and field conditions, which was 1.54-2.22 times than that of QY-1 (p < 0.05). The results indicated that 2% WSC treatment significantly increased the water-soluble and acid extractable Cd in rhizosphere soils of both B. napus cultivars. Furthermore, Cd concentrations in the oils of two B. napus cultivars with applied WSC (10 g·m-2) grown under field conditions were not significantly different from commercial rapeseed oils. Rapeseed oil of B. napus is not only an edible oil with high nutritional value, but it can also be converted into biomass diesel that can be used as a substitute for petroleum diesel.

Molecular mechanisms of intermuscular bone development in fish: a review.

Intermuscular bones (IBs) are slender linear bones embedded in muscle, which ossify from tendons through a process of intramembranous ossification, and only exist in basal teleosts. IBs are essential for fish swimming, but they present a choking risk during human consumption, especially in children, which can lead to commercial risks that have a negative impact on the aquaculture of these fish. In this review, we discuss the morphogenesis and functions of IBs, including their underlying molecular mechanisms, as well as the advantages and disadvantages of different methods for IB studies and techniques for breeding and generating IB-free fish lines. This review reveals that the many key genes involved in tendon development, osteoblast differentiation, and bone formation, e.g., scxa, msxC, sost, twist, bmps, and osterix, also play roles in IB development. Thus, this paper provides useful information for the breeding of new fish strains without IBs via genome editing and artificial selection.

A review of the Cypriniform tribe Yunnanilini Prokofiev, 2010 from China, with an emphasis on five genera based on morphologies and complete mitochondrial genomes of some species.

The loach tribe Yunnanilini from China is reviewed here using morphological characters and complete mitochondrial genomes of select species. Molecular data suggest that the tribe Yunnanilini is not monophyletic and can be divided into three clades. Species of the Yunnanilus nigromaculatus group form an independent genus and are placed in Eonemachilus. In the phylogenetic tree, Y. jinxiensis clusters with Paranemachilus genilepis, and Y. pulcherrimus clusters with Micronemacheilus cruciatus, indicating that Y. jinxiensis and Y. pulcherrimus belong to Paranemachilus and Micronemacheilus, respectively. Based on morphological data, Y. bailianensis and Y. longibarbatus are placed in Heminoemacheilus, while Y. jinxiensis and Y. pulcherrimus, are placed in Paranemachilus and Micronemacheilus, respectively. Yunnanilus niulanensis and Y. qujinensis are treated as junior synonyms of Eonemachilus caohaiensis. Eonemachilus, Micronemacheilus, and Yunnanilus are show short separation between anterior and posterior nostrils. The genera can be distinguished from each other by mouth structure, lateral line and cephalic lateral-line canals, and papillae on median part of both lips. The anterior and posterior nostrils of Heminoemacheilus and Paranemachilus are closely set. Paranemachilus and Micronemacheilus are distinguished by cheeks covered with scales and lips with papillae, respectively. Our phylogenetic tree and morphological characters support Traccatichthys as a valid genus, which can be distinguished from Micronemacheilus by anterior and posterior nostrils closely set (vs. clearly separated). Four species are placed in Traccatichthys.

Construction of a chromosome-level genome assembly for genome-wide identification of growth-related quantitative trait loci in Sinocyclocheilus grahami (Cypriniformes, Cyprinidae).

The Dianchi golden-line barbel, Sinocyclocheilus grahami (Regan, 1904), is one of the "Four Famous Fishes" of Yunnan Province, China. Given its economic value, this species has been artificially bred successfully since 2007, with a nationally selected breed (" S. grahami, Bayou No. 1") certified in 2018. For the future utilization of this species, its growth rate, disease resistance, and wild adaptability need to be improved, which could be achieved with the help of molecular marker-assisted selection (MAS). In the current study, we constructed the first chromosome-level genome of S. grahami, assembled 48 pseudo-chromosomes, and obtained a genome assembly of 1.49 Gb. We also performed QTL-seq analysis of S. grahami using the highest and lowest bulks (i.e., largest and smallest size) in both a sibling and random population. We screened two quantitative trait loci (QTLs) (Chr3, 14.9-39.1 Mb and Chr17, 4.1-27.4 Mb) as the major growth-related locations. Several candidate genes (e.g., map2k5, stat1, phf21a, sox6, and smad6) were also identified, with functions related to growth, such as cell differentiation, neuronal development, skeletal muscle development, chondrogenesis, and immunity. These results built a solid foundation for in-depth MAS studies on the growth traits of S. grahami.

[Spatial Distribution and Risk Assessment of Heavy Metal Pollution in Farmland Soils Surrounding a Typical Industrial Area of Henan Province].

In order to fully explore the spatial distribution of soil heavy metal contaminants in farmland soil surrounding a typical industrial area in Dakuai town, Xinxiang city, Henan Province, the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn in the surface soil and within the soil profile were determined and assessed. The principal components were also analyzed for source apportionment to provide a theoretical basis for the control and prevention of heavy metal pollution. According to the results, the soils in the study area are severely contaminated by Cd and Cu and moderated contaminated by As due to the battery manufacture and Cu (e.g., pipe and wire) processing. The concentrations of Cd, Cu, and As in soils were (2.56±1.23) mg·kg-1, (205.58±157.49) mg·kg-1, and (15.27±4.14) mg·kg-1, respectively, which exceeds standards by 100%, 89.44%, and 3.40%, respectively. Accounting for the influence of pollution sources, terrain, runoff erosion, and prevailing wind direction, all heavy metal concentrations were higher in the south direction, lower in the north direction. The concentrations of Cd and Cu in soil profile samples decreased with depth, with highest concentrations at the surface, indicating the strong effect of industrial activities. Arsenic concentrations varied little with soil depth due to its strong migration ability in alkaline soil, again suggesting an industrial source. Among them, the soil of study area was severely contaminated by Cd and Cu (Level 5). Cd poses a severe potential ecological risk (Level 5) and Cu poses a medium risk (Level 2) in the study soils, while other heavy metals show low potential ecological risk (Level 1). The order of the risk identified was Cd > Cu > Ni > As > Pb > Cr > Zn. In addition, the combined potential ecological risk of heavy metals in the target area is severe. The principal component analysis showed that the high As, Cd, and Cu contents are mainly derived from industrial areas. Therefore, it is urgent to remediate Cd and Cu soil contamination in this area and implement precautions to limit As contamination.

[Cd Accumulation Characteristics in Different Populations of Hylotelephium spectabile Under Salt Stress].

A pot experiment was conducted to investigate the growth response and Cd accumulation characteristics among different populations of Hylotelephium spectabile in Cd-contaminated cinnamon soil (2.22 mg·kg-1) with the addition of different concentrations of NaCl. Results showed that the biomasses and Cd concentrations of H. spectabile showed significant differences among different populations under Cd alone or Cd-salt combined stress. Moreover, salt stress aggravated the growth inhibition of H. spectabile and the Cd concentrations in different H. spectabile populations showed a declining trend, which may be related to the salt-derived pH increase leading to a decrease in Cd bioavailability. In addition, the growth and Cd absorption responses of H. spectabile under salt stress were significantly different in the different populations. The shoot biomasses of the LN population were significantly higher than in other populations under different treatment, and showed no significant decrease with the addition of 1% NaCl when compared with the control treatment and the tolerance index remained 0.91. At the same time, the shoot Cd concentration of the LN population was significantly higher than in other populations under different treatments. The result may be attributed to the Cd accumulation and detoxification mechanisms in LN are prior than other populations that may also have important physiological mechanisms for tolerance of salt stress. In summary, although Cd uptake in H. spectabile decreased with salt stress, there were significant differences among different populations. LN populations accumulated 84.4 µg·plant-1 Cd in shoots with 2% NaCl addition, which was 48.4%-89.3% higher than in other populations. Therefore, H. spectabile, especially LN populations, is a good candidate for phytoremediation of Cd-contaminated saline soil.

Restocking of Anabarilius grahami in Lake Fuxian, Southwest China: morphological and genetic effects.

The restocking of the endangered Kanglang white minnow ( Anabarilius grahami) in Lake Fuxian, China, has been conducted for 13 years. However, few studies have reported on the effectiveness of the captive breeding and release of this species. Here, we investigated variations in morphology, including body shape and skeletal deformities, and genetic features among hatchery-born and recaptured A. grahami from Lake Fuxian. Results showed that current hatchery-reared fish displayed a stubbier body shape than their wild conspecifics from the 1980s. Furthermore, high skeletal deformity ratios were found in two aquafarms (Luchong, 50%; Haikou, 45.2%), and the release of malformed fish elevated the skeletal deformity rate of wild stocks found near the Lake Fuxian release sites (west coast, 19.0%; east coast, 12.5%). Based on variations in the cytochrome b (cyt b) gene, existing A. grahami populations showed relatively high haplotype diversity and low nucleotide diversity. Hatchery populations exhibited reduced genetic variations based on microsatellite markers and reintroduction led to markedly lower genetic diversity around the west coast release sites of Lake Fuxian. Analysis of molecular variance (AMOVA) of cyt b and microsatellite analysis showed that the greatest genetic variations were found within populations, and genetic distance and Bayesian clustering analysis showed that the 14 populations clustered into one group. Based on morphological and genetic tests, we discuss corresponding recommendations, including release size, feed formulations, breeding strategies, and release tags, to minimize potential risks and improve hatchery practices for better restocking of this species.

[Effect of Nutrient Regulation and Control on Cd Accumulation Efficiency of Hylotelephium spectabile Under Field Conditions].

A field experiment with an orthogonally designed experiment L9(34) was designed to investigate the effect of different N, P, and K levels on plant growth and Cd uptake by Hylotelephium spectabile. The results showed that the biomass of H. spectabile significantly increased with the N application rate. The highest dry weight in the shoot occurred in the treatments with a high level of N (337.5 kg ·hm-2), which was 0.86-2.00 times higher than the value with no fertilizer treatment. The addition of K contributed to promoting the Cd absorption of H. spectabile, while no effect was observed when N and P were added. Consequently, NPK fertilizers contribute to increasing the Cd uptake of H. spectabile, and the N and K fertilizer play important role in plant growth and Cd absorption respectively. Moreover, the effect of fertilizers on Cd uptake of H. spectabile was in the order of N > K > P, which indicated that N fertilizer was the main factor for promoting the Cd phytoextraction efficiency of H. spectabile by increasing the biomass. Therefore, the application of high levels of N combined with moderate levels of P and K will be an effective approach to improve the Cd phytoremediation efficiency of H. spectabile by promoting its growth, and the Cd uptake can be increased by a factor of 0.9-2.2 compared to no fertilizer treatment condition.

[Tolerance Mechanism and Cadmium Enrichment Abilities in Two Brassica napus L. Cultivars].

A hydroponic experiment was conducted to explore the differences in growth status and Cd accumulation characteristics of two Brassica napus L. cultivars (QY-1 and SYH) under different concentrations of cadmium (Cd) stress (0, 2, and 5 mg·L-1). The Cd subcellular compartmentalization and antioxidant enzyme activities were determined to elucidate the intrinsic mechanism of the differences in the Cd accumulation capacity between the two cultivars of Brassica napus L. Furthermore, field trials were conducted to further verify the differences in phytoremediation of the two cultivars. Results show that neither of the cultivars exhibited obvious growth inhibition under Cd stress. Under the 2 mg·L-1 Cd condition, there were no significant differences in shoot Cd concentrations between the two cultivars. Under 5 mg·L-1 Cd condition, however, the Cd concentrations in both shoot and root of SYH were significantly higher than that of QY-1, which increased by 32.05% and 99.57%, respectively. In addition, the bioconcentration factor (BCF) of the root in SYH is significantly higher than that of QY-1. The subcellular Cd distribution in leaves of the two cultivars of Brassica napus L. showed that, with an increase of Cd stress, Cd concentrations of heat stable protein (HSP) and metal-rich granule (MRG) fractions in leaves significantly increased by 143.69% and 118.91% for QY-1, and by 63.34% and 118.91% for SYH. Thus, the segregation of Cd in HSP and MRG, which was reported to be biological detoxified metal fractions (BDM), might play an important role in the detoxification of Brassica napus L. at a subcellular level under Cd stress. Moreover, the distribution of Cd in the cellular debris fraction might be another important factor contributing to the differences in Cd accumulation of the two Brassica napus L. cultivars, which was 4.41 times higher in SYH than in QY-1 under Cd stress. The results of the antioxidant enzyme activities of two Brassica napus L. cultivars showed that, under the 5 mg·L-1 Cd condition, the antioxidant enzyme system may represent an important detoxification mechanism for QY-1 to cope with stress induced by high concentrations of Cd, while SYH is more effective in reducing the toxicity of Cd by separation of Cd into BDM fractions. The results of the field trial confirmed that the Cd concentrations in the above- and underground parts of SYH were 2.34 and 1.43 times higher than in QY-1, respectively. Therefore, SYH possess a higher Cd phytoextraction capacity than QY-1, and might be a good candidate for the remediation of moderate and mildly Cd-contaminated farmland.

Efficacy and Safety of Tongning Gel for Knee Osteoarthritis: A Multicentre, Randomized, Double-Blinded, Parallel, Placebo-Controlled, Clinical Trial.

OBJECTIVE: To evaluate the efficacy and safety of Tongning Gel (TNG) compared to placebo-controlled (PC) for knee osteoarthritis (KOA). METHODS: A multicentre, randomized, double-blinded, parallel, placebo-controlled, clinical trial was performed in 576 patients (432 patients in the TNG group, 144 patients in the PC group), and 1 in the experimental group withdrew due to nonuse of drug. Patients were randomized to receive TNG or PC applied to knee skin at 3g per time, 2 times per day, which lasted for 3 weeks. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score was used to evaluate the primary efficacy of TNG and WOMAC stiffness and physical function and total scores were used to evaluate the secondary efficacy of TNG. All participants who received at least one dose of study drug were included in the safety analysis. This trial has been registered in Chinese Clinical Trial Registry (no. CTR20131276). RESULTS: Primary efficiency outcome: there were significant differences in the decreased value of WOMAC pain score between two groups (P < 0.05), and the decreased value of WOMAC pain score in the TNG group were better than those in the PC group (P < 0.05). Secondary efficiency outcome: the WOMAC total score, WOMAC stiffness score, WOMAC physical function score, and the decrease of the above indexes of the two groups of patients after treatment were statistically significant (P < 0.05), and the improvement of the above indexes in the TNG group was better than that of the PC group (P < 0.05). Safety Evaluation. A total of 42 adverse events were reported by 29 patients: 25 adverse events reported by 16 patients (3.71%) in the experimental group and 17 adverse events were reported by 13 patients (9.03%) in the control group. And 8 adverse reactions were reported by 6 patients including 2 adverse reactions by 2 patients (0.46%) in the experimental group and 6 adverse reactions by 4 patients (2.78%) in the control group. Two cases of significant adverse events occurred in the experimental group. Both groups had one serious adverse event, respectively, which were not relevant to the intervention. CONCLUSION: These results of the trial demonstrate that TNG is superior to placebo in the treatment of patients with KOA, and TNG can improve other symptoms of KOA, such as stiffness and physical function. TNG is safe for the treatment of knee osteoarthritis as a whole.

From mainland to islands: colonization history in the tree frog Kurixalus (Anura: Rhacophoridae).

The origin and colonization history of Kurixalus, a genus of small arboreal tree frogs breeding exclusively in shallow swamps, is under disputed. On the basis of comprehensive sampling program, the evolutionary history of Kurixalus is investigated based on 3 mitochondrial genes. Our results indicate that the genus Kurixalus originated in the Asian mainland and subsequently arrived at its current distribution in Borneo, Taiwan, Ryukyu, and Hainan islands by a series of dispersal events. Moreover, the colonization of Taiwan from mainland Asia has occurred 2 times. The initial colonization of Taiwan occurred at 3.46-8.68 Mya (95% highest posterior density), which rejects the hypothesis that Kurixalus probably originated from Taiwan during the early Oligocene and favors the model of Neogene-origin rather than the model of Quaternary-origin for Taiwanese Kurixalus. Kurixalus eiffingeri has dispersed from Taiwan to the Ryukyus once or 2 times pending more data. Both transoceanic dispersal and landbridge dispersal have played a role in the colonization process; the former resulted in the colonization of Taiwan and the Ryukyus and the latter led to the colonization of Borneo and Hainan.

Sinocyclocheilus sanxiaensis, a new blind fish from the Three Gorges of Yangtze River provides insights into speciation of Chinese cavefish.

A blind fish of Sinocyclocheilus (Cypriniformes: Cyprinidae) was caught in open water in the Three Gorges (Sanxia) reservoir, at a depth of 20 m in the mainstream of Yangtze River in Zigui County, Hubei Province, China. This fish can be easily distinguished from all other congeners by external morphological characteristics, and is estimated to have diverged from its sister group about 0.55 million years ago (Ma). The geologically well separated locality of this species has expanded the distribution of Sinocyclocheilus cavefish from around N25°(latitude) to above N30°. Herein, we describe this new species as Sinocyclocheilus sanxiaensis sp. nov., and discuss the possible reasons why the species appears, surprisingly, in the Three Gorges reservoir.

Systematic relationships of Chinese freshwater semisulcospirids (Gastropoda, Cerithioidea) revealed by mitochondrial sequences.

The systematics of Semisulcospiridae in China is revised here based on morphological characters and mitochondrial phylogenetics. Phylogenetic relationships within the Chinese semisulcospirids were assessed via DNA sequences from mitochondrial analysis (cytochrome c oxidase I and 16S rRNA). This research contains most morphospecies of semisulcospirids previously recorded in China. Based on these results, the family of Chinese Semisulcospiridae is represented by three genera: i.e., viviparous Semisulcospira Böttger, 1886, oviparous Hua Chen, 1943 and Koreoleptoxis Burch and Jung, 1988. These genera can be distinguished from each other by reproductive anatomy, reproductive mode, and radula features. Species of Hua are mainly distributed in southwest China and Guangxi, whereas Koreoleptoxis and Semisulcospira are mainly distributed in south and northeast China.